Steep terrain and strong variability in surface temperatures are typical of mountain permafrost. The cross section in the foreground shows the complex distribution of subsurface temperatures characteristic of mountains, with the isotherms (lines linking points of equal temperature) nearly vertical in the ridge of the mountain. In the background, the colours on the mountain surface illustrate the strong variability in ground temperatures caused by...

Modelled permafrost temperatures (mean annual temperature at the permafrost surface) for the Northern Hemisphere (Arctic), derived by applying climate conditions to a spatially distributed permafrost model. (a) Present-day: temperatures averaged over the years 1980– 1999. Present-day climatic conditions were based on the CRU2 data set with 0.5° x 0.5° latitude/longitude resolution. (b) Future: projected changes in temperatures in comparison with ...

In Canada, recent evidence indicates a shortening of the freshwater-ice season over much of the country with the reduction being mainly attributable to earlier break ups. These trends match those in surface air temperature during the last 50 years. For example, similar spatial and temporal patterns have been found between trends (1966 to 1995) in autumn and spring 0°C isotherms (lines on a map showing location of 0°C air temperatures) and lake fr...

There has been a general increase in permafrost temperatures during the last several decades in Alaska, northwest Canada, Siberia, and northern Europe. Permafrost temperature records have been obtained uninterrupted for more than 20 years along the International Geosphere-Biosphere Programme Alaskan transect, which spans the entire continuous permafrost zone in the Alaskan Arctic. Records from all locations along the transect show a substantial w...

The extent of ozone depletion for any given period depends on complex interaction between chemical and climatic factors such as temperature and wind. The unusually high levels of depletion in 1988, 1993 and 2002 were due to early warming of the polar stratosphere caused by air disturbances originating in mid-latitudes, rather than by major changes in the amount of reactive chlorine and bromine in the Antarctic stratosphere.

Changes in ozone amounts closely follow temperature, with colder temperatures resulting in more polar stratospheric clouds that intensify ozone destruction. The results are compared from 1979 to 2006.

Future climate change and projected impacts: Increased growth and yield rates due to higher levels of carbon dioxide and temperatures could result in longer growing seasons. For example, in mid to high latitude regions, according to the Intergovernmental Panel on Climate Change’s (IPCC) Fourth Assessment Report moderate local increases in temperature (1-2ºC) can have small beneficial impacts on crop yields.

The Caucasus ecoregion covers an area of 580,000 km2, and includes six countries. The Greater Caucasus Mountain Range with its lofty peaks forms a formidable barrier between the northern and southern parts of the ecoregion. The Lesser Caucasus mountain chain extends across Georgia, Turkey, Armenia, Azerbaijan and into Iran. The climates in the regions mountaineous and temperature.

The more recent history, from the middle ages and up until now, show increasing temperatures, rising as the world emerged from the Little Ice Age (LIA), around 1850. With the industrial era, human activities have at the same time increased the level of carbon dioxide (CO2) in the atmosphere, primarily through the burning of fossil fuels. Carbon dioxide is one of the main greenhouse gases, and scientists have been able to connect human activities ...

Antarctica is the coldest, driest and windiest continent on Earth. This graph shows the annual temperatures and seasonal variation at three locations in Antarctica - the research bases Bernardo O'Higgins (Chile - on the Antarctic Peninsula), Scott Base (New Zealand - Ross Island) and one of the coldest places on the planet - the Vostok station (Russia - at the center of the East Antarctic Ice Sheet). The surface temperatures are long term average...

Warming is widespread, generally greater over land than over oceans, and the largest gains in temperatures for the planet are over the North American Arctic, north central Siberia, and on the Antarctic Peninsula. These recent increases in temperature are confirmed by changes in other features: loss of sea ice, shift of tundra to shrub vegetation, and migration of marine and terrestrial ecosystems to higher latitudes.

Climate change, due to increased concentrations of greenhouse gases in the atmosphere, has lead to increased temperatures and large scale changes in the Arctic. The Arctic sea ice is decreasing, permafrost thawing and the glaciers and ice sheets are shrinking. The projected climate situation in 2090 are presented in this figure, the temperatures are annual values from the NCAR-CCM3 model, ensemble averages 1-5 for the SRES A2 experiment. The ice ...

Global climate change may impact food production across a range of pathways (Figure 17): 1) By changing overall growing conditions (general rainfall distribution, temperature regime and carbon); 2) By inducing more extreme weather such as floods, drought and storms; and 3) By increasing extent, type and frequency of infestations, including that of invasive alien species (dealt with in a separate section).

Figure 24: Possible individual ranges of yield and cropland area losses by 2050 with climate change (A2 scenario), non-food crops incl. biofuels (six OECD scenarios), land degradation (on yield and area, respectively, see text), water scarcity (including gradual melt of Himalayas glaciers, see box and text) and pests (invasive species of weeds, pathogens and invertebrates such as insects, see text). Although these effects may be considerable, ...

Weather patterns are altered.

Average surface temperature anomaly (oC)

Summary of arctic amplification depicted from one of the climate models participating in the Intergovernmental Panel on Climate Change Fourth Assessment Report (IPCC 2007).

The temperature regime of sub-sea permafrost is determined by the annual temperature of the surrounding seawater, just like the thermal regime of terrestrial permafrost is determined by the arctic surface temperature.

Initially, meltwater was assumed to be the prime cause of glacier acceleration, making its way to the ground beneath ice sheets, lubricating it and causing the glaciers to flow more quickly to the sea.

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